Bowling ball insert structure

ABSTRACT

To facilitate adjustment of span and pitch, the insert comprises a cylindrical casing mountable within a radial bore in a bowling ball, a cylindrical sleeve rotatable in the casing about a radius of the ball and having an aperture angled to the ball radius, and a plug rotatable in the aperture and having an off-center thumb (or finger) hole. In one rotative setting of the sleeve and plug the outer end of the thumb hole is coaxial with the ball radius. From this setting, rotation of the plug only adjusts pitch and span; rotation of both the plug and sleeve together adjusts pitch only; and rotation of the plug and sleeve relative to each other and to the ball produces variations in the span and pitch adjustments.

Umted States Patent 1 [111 3,861,681

Kelsey Jan. 21, I975 BOWLING BALL INSERT STRUCTURE [57] ABSTRACT [76] Inventor: Calvin F. Kelsey, 2755 E. Maple Rd., Birmingham, Mich. 48008 To facilitate adjustment of span and pitch. the insert comprises a cylindrical casing mountable within a ra- [22] Flled' 1973 dial bore in a bowling ball, a cylindrical sleeve rotat- [21] Appl. No.1 413,644 able in the casing about a radius of the ball and having an aperture angled to the hall radius, and a plug rotatable in the aperture and having an off-center thumb 273/63 (or finger) hole. In one rotative setting of the sleeve and plug the outer end of the thumb hole is coaxial [58] Flew of Search 273/63 33/]74 F with the ball radius. From this setting, rotation of the plug only adjusts pitch and span; rotation of both the [56] UNITE SSFI T?ES ;:2 FENTS plug and sleeve together adjusts pitch only; and rotation of the plug and sleeve relative to each other and 2,372,959 4/l945 Keith 273/63 B to the ball produces variations in the span and pitch 3,001,793 9/196 lnsetta 273/63 B adjus[men[s Primary Examiner-George .l. Marlo Attorney, Agent, or FirmBarnes. Kisselle, Raisch &

Choate 47 Claims, l8 Drawing Figures PAIENIEU 1 3. 86 1.681

SHEET 10F 5 FIG. I

PATEIITED 3,861.68 1

SHEET 2 OF 5 160 CENTER OF THUMB HOLE 6O 62: AXIS OF THUMB HOLE 60 R: US OF BALL AXIS OF figTATION OF SLEEVE 6A: AXIS OF ROTATION OF PLUG 56 E: CENTER OF BALL Fig-2A Y'ATENTED JANZI I975 SHEET 4 [1f 5 PATENTEU JANE] SHEET 5 OF 5 FIG. l5

. l BOWLING BALL INSERT STRUCTURE This invention relates generally to bowling balls and more particularly to an insert which can be affixed within a bore in a bowling ball having elements which can be manipulated to adjust the span and pitch of a thumb hole (or finger hole) relative to another hole or holes utilized to grip the ball.

The term span is generally used to denote the distance between a thumb hole and finger hole while the term pitch" is generally used to denote the orientation of the center line of a thumb hole relative to the center of the ball and the finger hole or holes. To achieve optimum bowling performance an individual must have a ball provided with the particular span and pitch combination which best fits his hand and suits his particular mode of delivering the ball. Individuals hands and fingers vary in size and configuration and the mode of delivery varies from individual to individual. Thus, optimum span and pitch combination varies from person to person. Moreover, the optimum combination may vary for an individual bowler according to variations in the particular characteristics of different bowling alleys.

Conventionally a bowler obtains a ball having the best combination of span and pitch by trial and error, sometimes supplemented by measuring devices. This frequently entails the purchase of a succession of bowling balls having finger and thumb holes drilled differently, a procedure which is both lengthy and costly. If a bowler bowls on alleys having substantially differing characteristics. he may have to have two or more bowling balls provided with different span and pitch combinations.

Heretofore, efforts have been made to provide thumb hole and finger hole inserts in bowling balls manipulable to adjust span and pitch. Insofar as I am aware, no such inserts have been satisfactory for one or more of several reasons. First, the range of adjustment of either span or pitch has been inadequate and second, no such insert has been capable of providing a suitable variety of combined span and pitch adjustments. Third, the adjustments have been awkward if not difficult to effect, utilizing such devices as set screws within the confines of the ball. Finally, no such inserts have met American Bowling Congress specifications which require that no part of the insert be removable without destruction thereof and that no metal parts he used.

The object of the present invention is to provide a relatively simple, inexpensive bowling ball insert structure which is improved to eliminate the above discussed deficiencies in the prior art structures. In the accompanying drawings:

FIG. I is a top plan view of a bowling ball having an insert according to the present invention.

FIG. 2 is an enlarged scale sectional view on line 22 of FIG. 1.

FIG. 2A is a partly diagrammatic sectional view generally similar to FIG. 2 but with the interlocking components omitted.

FIG. 3 is an enlarged scale, fragmentary plan view of a portion of the ball shown in FIG. 1.

FIG. 4 is a view similar to FIG. 3 but showing certain parts in a different position.

FIG. 5 is an elevational view of the outer casing of the insert.

FIG. 6 is a sectional view on line 6-6 of FIG. 5.

FIG. 7 is an elevational view ofa sleeve forming part of the insert.

FIG. 8 is a sectional view on line 8-8 of FIG. 7.

FIG. 9 is an elcvational view of a plug forming part of the insert.

FIG. I0 is an enlarged scale, fragmentary view of a portion of the insert shown in FIG. 2, this view illustrating a modified form of the invention.

FIG. 11 is a view generally similar to FIG. 2 but showing the modified form of the invention illustrated in FIG. 10.

FIG. 12 is a fragmentary plan view of a portion of a ball having an insert according to the present invention.

FIG. 13 is an enlarged scale sectional view on line 13-13 of FIG. lI.

FIG. 14 is a diagrammatic view illustrating movements in the outer end of the thumb hole upon turning the sleeve and plug within the outer casing.

FIG. I5 is a diagrammatic plan view illustrating movement of the thumb hole when the sleeve and plug are rotated together from an initial setting.

FIG. 16 is a diagrammatic view in elevation representing the thumb hole movement illustrated in FIG. I5.

FIG. 17 is a diagrammatic view in elevation illustrating movement of the thumb hole when the plug only is rotated.

Shown in the drawings is a bowling ball 20 having a pair of finger holes 22,24 and having a radial bore 26 within which an insert 28 according to the present invention is affixed. A radius R of the ball passes through the center of bore 26.

In the illustrated form of the invention insert 28 includes an outer cup-shaped casing 30 having a cylindrical side wall 32 engaged within bore 26 and a bottom wall 34 engaged against the bottom 36 of the bore. Casing 30 is permanently affixed within bore 26 by such means as adhesive between casing walls 32,34 and the portions of bore 26 engaged thereby. Casing wall 30 has an interior surface 38 which is substantially cylindrical and the axis of which is substantially coincident with ball radius R.

Rotatably mounted within casing 30 is a sleeve 40 having a side wall 42 with a substantially cylindrical exterior 44 rotatably engaged with interior surface 38 of casing 30. Sleeve 40 has a bottom wall 46. Internally, sleeve wall 42 defines a longitudinal aperture 48 which is substantially cylindrical and the axis of which is disposed at an angle to the axes of wall exterior 44 and casing interior 38. Consequently, sleeve wall 42 at one circumferential location 50 is radially relatively thick adjacent top end 52 and diametrically opposite from location 50 at location 54 wall 42 is radially relatively thin (FIGS. 2 and 2A). The radial thickness of the top end of the sleeve varies progressively proceeding circumferentially between locations 50 and 54. Also, progressing longitudinally downwardly from location 50 the thickness of wall 42 progressively diminishes while progressing downwardly from location 54 the wall thickness progressively increases.

A plug 56 is mounted within aperture 48. Plug 56 has a substantially cylindrical exterior surface 58 which is rotatably engaged with the surface defining aperture 48. The plug has a longitudinal hole 60 therein which in the illustrated form of the invention is the thumb hole by which, together with finger holes 22,24 ball 20 is gripped by a bowler. Hole 60 is substantially cylindrical and its axis 62 is off center with respect to the axis or center line 64 of plug 56. In the structure illustrated axes 62,64 are parallel to one another and both are angled with respect to radius R of ball 20, the angle of axis 62 being shown at A (FIGS. 2, 2A and I6). Because of the eccentric location of hole 60 the wall of the plug between its outer surface 58 and hole 60 at one circumferential location 66 is radially relatively thin while at location 68 diametrically opposite the plug wall has a greater radial thickness, The radial thickness of the plug wall varies progressively progressing circumferentially between locations 66 and 68.

Sleeve wall 42 at its relatively thick portion 50 has a longitudinal way 70 therein having a relatively large diameter oblong portion 72 and a relatively small diameter portion 74 which adjoin at a radial shoulder 76. A plunger 78 is longitudinally slidable within way 70. The plunger has portions 80,82 of relatively larger and smaller diameter which fit respectively in larger and smaller diameter portions 72,74 of way 70. Plunger portions 80,82 adjoin at a shoulder 84. A coil spring 86 is compressed between shoulders 76,84 to urge the plunger upwardly as the drawings are viewed. The plunger is maintained within passageway 70 against the spring force by such means as a snap ring 86 on the lower end 90 ofthe plunger engaged with a shoulder 92 on sleeve 40.

Sleeve 40 is permanently retained within casing 30 and for this purpose casing wall 32 is provided with an opening 94 which contains a ball 96 projecting radially inwardly into an annular groove 98 in the exterior of sleeve wall 42. Ball 96 is obstructed from outward dis engagement from within groove 98 by the surface of bore 26.

The interior of easing wall 32 is provided with a number of circumferentially distributed detent recesses I00, eight being illustrated. Sleeve wall 42 has an pen ing I02 between its outer surface 44 and small diameter portion 82 of way 70. Opening 102 is longitudinally positioned so that when sleeve 40 is rotated, opening 102 can be registered selectively with recesses I00. A detent ball I04 is carried within opening I02.

Ball 104 has a diameter greater than the thickness of sleeve wall 42 between its outer surface 44 and way 70. When opening I02 and ball 104 are aligned with a recess I00 and plunger 78 is in the upward position of FIG. 2, ball 104 projects radially outwardly from hole 102 into locking engagement within the recess. The plunger has a portion 106 engaged against the inner side of ball I04 to obstruct movement of the ball inwardly out of engagement from the recess thereby locking sleeve 40 in a selected rotative position within casing 30.

The plunger has a relieved portion 108 above obstructing portion I06. Relief I08 has tapered upper and lower portions as shown. When the plunger is depressed, relieved portion 108 aligns with ball I04 and when turning force is applied to sleeve 40 the ball is cammed inwardly out of detent recess I00 into relieved portion 108 permitting the sleeve to be turned to another rotative position within casing 30. When ball 104 aligns with another recess I00 and plunger 78 is released. the plunger is returned upwardly by spring 86 and the ball is cammed outwardly into locking engagement within the recess by the tapered bottom wall of relieved portion 108.

Plug 56 is retained rotatably within sleeve 40 by means of a ball ll0 carried within an opening H2 in wall 42 of sleeve 40 between aperture 48 and way 70. This ball projects radially inwardly into an annular groove 114 in the exterior of plug 56. Plunger 78 has a portion I16 which engages the outer side of ball H0 and obstructs movement of the ball out of engagement with groove I14.

In noncompetition bowling balls it is desirable that plug 56 be removable for replacement by other plugs having thumb holes 60 of different characteristics. A dual release for plug 56 is provided for this purpose. One part of the release comprises an inwardly facing relieved portion II8 of plunger 78 having tapered upper and lower wall portions as shown. When plunger 78 is depressed beyond the position in which relief 108 aligns with ball I04, relief 118 aligns with ball so that when upward force is exerted on plug 56 ball 110 can be cammed out of groove I14 into relief H8. The other part of the dual release resides in the releasable lock which secures plug 56 in selected rotative positions in sleeve 40.

A plunger 120 is slideably mounted in a longitudinal way 122 in the thicker wall portion 68 of plug 56. This way has portions 124.126 respectively of larger and smaller diameter which adjoin at a shoulder I28. Larger portion 126 has oblong shape. Plunger I20 has portions 130,132 which fit respectively in way portions l24,l26 and adjoin at a shoulder I34. A coil spring I36 is compressed between shoulder I28 and 134. Plunger 120 is retained within way I22 against the force of spring I36 by a snap ring I38 around the lower end I40 of the plunger and engaged against a shoulder I42 on plug 56.

Wall portion 68 ofthe plug has an opening 144 which extends between way I22 and outer surface 58 of the plug. A ball I46 is carried within this opening and has a diameter greater than the wall thickness between way 122 and plug exterior 58. The ball projects outwardly into a selected one of a circumferentially distributed series oflocking recesses I48 in the wall defining sleeve aperture 48, eight such recesses being illustrated. In the upward position of plunger I20 a portion thereof engages the inner side of ball I46 and obstructs movement thereof inwardly out of engagement with recess 148. Above I50 the plunger has a relieved portion I52 with tapered upper and lower portions as shown.

When plunger 120 is depressed, relief I52 aligns with detent ball 146 so that when turning force is exerted on plug 56 the ball is cammed out of recess 148 into relief I52. The plug can then be turned to a different rotative position wherein ball I46 aligns with another detent recess 148. When the plunger is released, it is returned upwardly by spring I36 and the tapered lower wall portion of relief 152 cams ball I46 into the recess 148 newly aligned therewith to lock the plug in its new rotative position within sleeve 40.

To remove plug 56 from within sleeve 40 plunger 78 is depressed to align relief I18 therein with ball 110 and plunger I20 is depressed to align relief I52 therein with ball 146. When upward force is exerted on the plug, balls IIO and I46 are cammed out of engagement respectively with groove [I4 and recess 148 which releases the plug for removal from the sleeve. The dual release structure for removing plug 56 is advantageous in that a bowler must use both hands. Thus, he cannot accidentally release the plug for removal while manipulating either plunger 78 or I individually. This insures that the plug will not be accidentally pulled out of sleeve 40 during bowling.

The upper or exposed ends of casing 30, sleeve 40 including the plunger ends, and plug 56 are shaped so that they conform very nearly to the spherical surface defined by the exterior of ball 20. The upper edge portions of casing are provided with a circumferential array of eight numerals (0 through 7) showing the circumferential location of detent recess 100. Similarly, the upper edge portions of plug 56 are provided with a circumferential array of eight numerals showing the circumferential locations of detent recesses 148. The numerals on the plug are arranged in two groups of I through 4 progressing clockwise and counterclockwise from 0. The numeral 4 is actually provided on the exposed end of plunger 120.

The larger diameter portions 80,130 of plungers 78,120 respectively provide manually depressible buttons. The exposed end of plunger 78 is provided with a mark 154 having the form of a double ended pointer, the outer point 156 providing an index for aligning sleeve at selected rotative positions within casing 38 and the inner point 158 providing an index for aligning plug 56 at selected rotative positions within sleeve 40. The oblong shape of the larger portions of plungers 78,120 and ways 70,122 secures index mark 154 and numeral 4 on plug 56 in their proper rotative positions.

When sleeve 40 is adjusted so that index 156 is at the zero setting on casing 30 and with plug 56 adjusted so that its zero setting is aligned with inner index I56, the parts are in the position illustrated in FIGS. 2, 2A and 12 and the solid line position of FIG. 3. The orientation of thumb hole 60 is also illustrated in solid lines in FIGS. 16 and 17 and in the left-most view of FIG. 15. The center 160 of the outer end of the thumb hole is substantially centered within casing 30 and is substantially coincident with radius R of ball 20. In this position the span, that is, the distance between the outer end of the thumb hole and finger holes 22,24 is at an intermediate adjustment and the pitch of the thumb hole is somewhat closed.

In general parlance pitch is referred to as the orientation of the center line or axis of the thumb hole relative to the center of the ball and the finger holes. However, pitch is frequently measured or expressed as the distance d (FIGS. 16 and 17) between the thumb hole axis or center line 62 and a radius R of the ball at the center C of the ball. When the axis of the thumb hole is closer to the finger holes than the 'ball radius, the pitch is said to be closed or positive and when the thumb hole axis is further from the finger holes than the ball radius the pitch is said to be open or negative. Closed or positive pitch and open or negative pitch are represented in FIGS. 16 and I7 as +d and -d respectively.

Referring to FIGS. 2A, 12 and the solid line position of FIG. 3 wherein the outer end 160 of thumb hole 60 is centered with respect to casing 30 it will be noted that the upper ends of sleeve 40 and plug 56 have a uniform combined radial thickness T (FIG. 2A) everywhere around the thumb hole. Consequently, when sleeve 40 is rotated within casing 30 carrying plug 56 with it, the upper end of thumb hole 60 remains centered within casing 30 and the span remains constant.

However, because of the angle A (FIGS. 2, 2A and 16) of thumb hole axis 62 with respect to the axis of rotation of sleeve 40 (radius R) the lower end of the thumb hole describes an are around radius R. When sleeve 40 is rotated either clockwise or counterclockwise so that index 156 moves from zero setting to number 4 setting H rotation) the thumb hole moves from the solid line position of FIG. 16 to the broken line position thereof. This movement is also illustrated in plan in FIG. 15 wherein the numerals 0-4 represent the settings of index 156. While span remains constant the pitch shifts from positive or closed to negative or open, i.e., from +d to -d.

At the number 2 and number 6 settings of index I56 pitch is zero or neutral since distance d is neither positive or negative. At settings 1 and 7 pitch is positive but less so than at zero, and at settings 3 and 5 pitch is negative but less so than at 4. When index 156 is at settings I, 2, or 3 thumb hole 60 is either canted to the right of left, and when index 156 is at setting 5, 6, or 7 the thumb hole is canted to the opposite hand.

FIG. 4 (solid lines) and FIG. 17 illustrate adjustments of thumb hole 60 when plug 56 is turned within sleeve 40 while index 156 remains at the zero setting with respect to casing 30. When plug 56 is so turned, the center line or axis 62 of the hole bodily describes an are around the axis or center line 64 of the plug since axis 62 and center line 64 are parallel. In turning the plug l80 in either direction from its zero setting to its number 4 setting withe respect to index 158, the thumb hole moves from the solid line position to the dotted line position of FIG. 17 and from the solid line position of FIG. 3 to the solid line position of FIG. 4.

The upper end of thumb hole 60 moves to the right thereby increasing the span. At the same time thumb hole axis 62 shifts bodily so that pitch is changed from positive or closed (4 d) to negative or open (-d). This is particularly advantageous since characteristically the greater the span which a bowler selects the more open is the corresponding suitable pitch. In the I, 2, or 3 set tings these variations in pitch and span will be in between the zero and 4 settings and the thumb hole will be displaced somewhat to the right or left hand depending upon which set of numerals l, 2, 3, is employed. Identical changes in pitch are produced by rotating plug 56 alone through a given angle and by rotating sleeve 40 together with plug 56 through the same angle.

It will be apparent that by rotatably adjusting sleeve 40 and plug 56 relative to each other and relative to casing 30, combinations of the movements illustrated in FIGS. 16 and 17 can be effected to achieve different combinations of span and pitch settings and to achieve adjustments of greater magnitude than those illustrated in FIGS. 16 and 17.

A number of these adjustments are represented diagrammatically in FIG. 14 wherein thumb hole 60 is shown on an enlarged scale for the sole purpose of demonstrating the approximate scale of these adjustments. The center of the outer end of thumb hole 60 at zero, zero settings of indices 156,158 is represented at 160. The outer series of numbers zero through 7 represents the settings on casing 30 and the two inner series zero through 4 represent the settings on plug 56. If plug 56 alone is rotated through 360 while sleeve 40 remains stationary, hole center 1650 will follow the path of circle 162, the eight dots on this circle representing successive locations of center 160. This motion is described above with respect to FIG. I7.

If plug 56 is moved to either setting number 1 and sleeve 40 is rotated through 360, center I60 will describe circle I64, the eight dots on this circle representing the location of center 160 at the eight settings ofthe sleeve relative to casing 30. If the plug is rotated to either setting number 2 and sleeve 40 is then rotated through 360, center I60 of opening 60 will describe the circle 166. the eight dots on this circle again representing the location of center I60 at the eight settings on casing 30.

If the plug is rotated to either setting number 3 and sleeve 40 is rotated through 360", center I60 will describe circle 168, the eight dots on this circle representing the location of center 160 at the eight settings on casing 30. Finally, if plug 56 is rotated to the number 4 position and sleeve 40 is rotated through 360, center 160 will describe circle I70. the dots on this circle again representing the location of center 160 at the eight settings on casing 30.

Certain of these adjustments are represented physically in FIGS. 3 and 4. When plug 56 alone is turned from its zero setting to its number 4 setting, thumb hole 60 moves from the solid line position of FIG. 3 to the dotted line position, the center I60 of its outer end following circle I62. The dotted line position of FIG. 3 is also shown in solid lines in FIG. 4. Thereafter when sleeve 40 is turned, for example counterclockwise. thumb hole 60 moves from the solid line position of FIG. 4 to the dotted line position, center I60 moving on circle 170.

From an inspection of FIG. I4 it will be seen that there are 33 possible positions of thumb hole 60 with respect to finger holes 22,24. The number of settings could be increased or decreased as desired by varying the number of detent recesses I02 and I48 in casing 30 and sleeve 40 respectively.

Since sleeve 40 and plug 56 can both be turned to settings to the right and left of the center line -4 of casing 30, thumb hole 60 can be adjusted to positions for accommodating both right and left hand bowlers.

Casing 30, sleeve 40, plug 56, and plungers 78 and I ofa typical insert 28 according to the invention are made of a relatively tough nonmetallic plastic material such as that available commercially under the trademark Valox, a product of General Electric Co. These parts are injected molded and subsequently machined so that they interfit nicely. Ball 96 and detent balls I04, 110, and I46 typically are also made of a plastic material such as nylon.

It is contemplated that in commercial practice of the invention a preferred structure will be one wherein the difference in thickness between sleeve wall portions 50,54 and the difference in thickness between plug wall portions 66,68 are substantially equal and wherein these differences and angle A are coordinated so that when the end of thumb hole 60 adjacent the surface of ball 20 is moved through a given distance either by rotation of plug 56 alone or by rotation of both the plug and sleeve 40, the point on thumb hole axis 62 closest to ball center C will be varied by a predetermined fraction of the distance through which the outer end of the thumb hole moves.

By way of example, for a standard bowling ball having a radius of about 4.25 inches, a typical insert 28 has a height of about 3 inches and an overall diameter of about 2% inches; sleeve 40 has a diameter of about 2.25 inches and plug 56 has a diameter of about L75 inches; the difference between plug wall thicknesses 66,68 is about inch and the difference between sleeve wall thicknesses 50,54 is also about inch. thereby providing for a maximum span variation of about /1 inch; this span variation produces a variation in pitch (distance d) of about inch and as can be shown trigonometrically, angle A is about 2, 36 min. to produce this pitch variation. The difference in wall thicknessess 50,54 and 66,68 can be varied as desired in different inserts 28 and angle A will be varied commensurately to produce a pitch variation (distance d) which is one-half (or other desired fraction) ofthe span variation as described above.

Similarly, inserts made for bowling balls of different diameters may have different heights, in which case angle A may be varied commensurately to the wall thickness differences to provide the span-pitch variation relation described above.

In the form of the invention illustrated in FIG. 2 springs 86 and I36 can comprise conventional metal coil springs since the insert 28 illustrated therein is intended for noncompetition use. An insert 28 is relatively inexpensive, the cost of manufacture at limited production rates being estimated at about $3.75 to $4 each. At higher production rates the cost of an insert 28 would be substantially less.

The modified insert 28a illustrated in FIGS. 10, II, and I3 is similar to insert 28 except that springs 86a and 136a are made of a plastic material such as Delrin, a product of General Electric Co. Plunger 78a is slightly modified in that the portion 172 thereof surrounded by spring 860 has slightly smaller diameter to accommodate the larger cross section of the material of this spring. When plunger 78a is depressed, relief 108 therein aligns with detent ball 104 to free sleeve for rotational adjustment of thumb hole as in the form of the invention described above.

However. in this position of the parts spring 86a is compressed to solid condition or very nearly so as shown in FIG. 10. The plunger cannot be further depressed to align relief 118 therein with ball 110. Therefore, plug 56 cannot be removed from within sleeve 40 without destruction of some of the parts of the insert. Insert 28a thus meets the requirements of the American Bowling Congress specifications that in a competition ball there may be no metal parts and no part of the ball may be removed without destruction.

The particular mode of use of insert 28 or 280 will depend upon the individual bowler. In general, either sleeve 40 or plug 56 will be initially released by depressing its respective plunger 78 or I20 and the sleeve or insert will be turned to an initial trial adjustment of span and/or pitch. Thereafter, refinements of the adjustment, if required, will be effected by turning the sleeve and plug individually or together. When the individual has found the best combination of pitch, span, and right or left handed orientation of thumb hole 60, he notes the combination of index numbers on casing 30 and plug 56 for future reference.

If an individual bowler bowls on alleys having substantially differing characteristics, he may employ a dif ferent combination of index settings for each alley. A single ball may be used by several individuals, for example various members ofa family, and each individual can adapt ball 20 to his particular hand by using a particular predetermined combination of index settings.

It is contemplated that in commercial use a selection of sleeves 40 and plugs 56 will be provided which will enable a great majority of bowlers by proper selection of a sleeve and plug combination to obtain the opti mum combination ofspan and pitch settings for his particular hand and mode of delivery.

As will be obvious, the present invention can be utilized to provide adjustable finger holes as well as thumb holes.

I claim:

1. Insert structure adapted to be mounted within a radial bore in a bowling ball, said insert structure comprising,

means forming a sleeve and mounting means adapted to mount said sleeve within such radial bore for rotation about an axis substantially coincident with a radius of the ball through the bore,

said sleeve having a wall which defines an aperture therein having surface portions lying on a cylinder, the axis of which is angled in non parallel relation to the axis of rotation of said sleeve,

means forming a plug engaged within said aperture for rotation relative to said sleeve about said aperture axis,

said plug having a hole which is eccentrically located therein and which is adapted to receive a human digit,

said sleeve and plug having end portions adapted to be located adjacent the surface of a sphere defined by the ball and said hole having an end which opens adjacent said surface,

the angle of said aperture axis and the eccentricity of the location of said hole being so related that in one rotative position of said plug and sleeve relative to each other, said end of said hole is substantially centered with respect to said axis of rotation of said sleeve.

2. The structure defined in claim 1 wherein said hole has an axis which is substantially parallel to that of said aperture.

3. The structure defined in claim I wherein said hole has an axis which is angled in non parallel relation to that of said aperture.

4. The structure defined in claim 1 wherein said mounting means comprises a casing adapted to be affixed within such radial bore,

said casing having a wall with internal surface portions lying on a cylinder the axis of which is substantially coincident with a radius of the ball through the bore,

said sleeve being engaged within said surface portions for rotation about the latter said axis relative to said casing. said casing having an end portion adjacent the surface of such sphere.

5. The structure defined in claim 4 wherein said casing comprises a cup having a substantially cylindrical exterior and a substantially cylindrical interior which defines said internal surface portions,

said sleeve having a substantially cylindrical exterior so engaged within said surface portions and said aperture wall being substantially cylindrical,

said plug having a substantially cylindrical exterior so engaged within said aperture and said hole therethrough being substantially cylindrical.

6. The structure defined in claim 5 wherein each of said casing, sleeve, and plug is formed of a nonmetallic material.

7. The structure defined in claim 5 wherein in said one rotative position of said plug and sleeve. a first of said end portions of said sleeve at one side of said aperture is radially relatively thick and a first of said end portions of said plug radially contiguous thereto is radially relatively thin. a second of said end portions of said sleeve diametrically opposite from the first is radially relatively thin and a second of said end portions of said plug radially contiguous thereto is radially relatively thick.

8. The structure defined in claim 7 wherein the combined radial thickness of said first portions is substantially equal to that of said second portions.

9. The structure defined in claim 4 and including in addition first releasable locking means operable to secure said sleeve in selected rotative positions within said casing, and second releasable locking means operable to secure said plug in selected rotative positions within said sleeve.

10. The structure defined in claim 9 wherein said sleeve has substantially cylindrical exterior surface portions engaged within said internal surface portions of said casing, one of said surface portions having an annular groove, and means projecting from the other of said surface portions into said groove to retain said sleeve rotatably within said casing.

11. The structure defined in claim l0 wherein said groove is in said exterior surface portion of said sleeve.

12. The structure defined in claim 9 wherein said first locking means comprises a plurality of detent recesses in said internal surface portions of said casing at said selected positions,

a detent member carried by said sleeve movable outwardly into locking engagement within a selected recess and inwardly out of engagement with said recess,

and a locking member carried by said sleeve movable between one position in which it obstructs inward movement of said detent member and another position in which is frees said detent member for inward movement.

13. The structure defined in claim 12 wherein said locking member is carried within said sleeve wall between the exterior thereof and said aperture, said detent member being contained within an opening between said exterior of said wall and said locking member.

l4. The structure defined in claim 13 wherein said locking member comprises a plunger movable generally longitudinally within said wall, said plunger having an obstructing portion which in said one position of said plunger so obstructs said detent member and having a relieved portion which in said other position is aligned with said detent member to so free the same.

15. The structure defined in claim 14 wherein said member comprises a ball.

l6. The structure defined in claim l4 wherein said plunger has an exposed end portion which in said one position thereof is adjacent said end portion of said sleeve, said plunger being spring-biased toward said one position and being manually shiftable against the bias toward said other position of said plunger.

[7. The structure defined in claim 16 wherein said sleeve wall has a longitudinally extending way therein which has a relatively small diameter portion and a relatively large diameter portion with a shoulder therebetween,

said plunger having portions of relatively small and relatively large diameter which respectively fit movably within said small and large diameter portions of said way and having a shoulder between said small and large diameter portions,

said small diameter portion of said plunger embodying said obstructing portion and relieved portion thereof,

and a spring stressed between said shoulders to provide said bias.

[8. The structure defined in claim 17 wherein said relatively large diameter portion of said plunger has said exposed end portion.

19. The structure defined in claim 9 wherein said secand locking means comprises a plurality of detent recesses in said aperture wall at said selected positions of said plug,

a detent member carried by said plug movable outwardly into locking engagement within a selected recess and inwardly out of engagement with the recess,

and a locking member carried by said plug movable between one position in which it obstructs inward movement of said detent member and another position in which it frees such detent member for inward movement.

20. The structure defined in claim 19 wherein said locking member is carried within the wall of said plug between the exterior thereof and said hole therein, said detent member being contained within an opening between said exterior of said wall and said locking member.

21. The structure defined in claim 20 wherein said locking member comprises a plunger movable generally longitudinally within said wall of said plug, said plunger having an obstructing portion which in said one position of said locking member so obstructs said detent member and having a relieved portion which in said other position is aligned with said detent member to so free the same.

22. The structure defined in claim 21 wherein said detent member comprises a ball.

23. The structure defined in claim 21 wherein said plunger has exposed end portions which in said one position thereof are adjacent said end portion of said plug, said plunger being spring-biased toward said one position and being manually shiftable against the bias toward said other position of said plunger.

24. The structure defined in claim 23 wherein said plug has a longitudinal way therein which has a relatively small diameter portion and a relatively large diameter portion with a shoulder therebetween,

said plunger having portions of relatively small diameter and relatively large diameter which respectively fit movably within said small and large diameter portions of said way and having a shoulder between said small and large diameter portions.

said small diameter portion of said plunger embodying said obstructing portion and relieved portion thereof,

and a spring stressed between said shoulders to provide said bias.

25. The structure defined in claim 24 wherein said relatively large diameter portion of said plunger has said exposed end portion.

26. The structure defined in claim 9 and including in addition third releasable locking means operable to secure said plug rotatably within said aperture, said third locking means being cooperable with said second locking means when both are in released condition to free said plug for removal from within said aperture.

27. The structure defined in claim 26 wherein said first and third locking means are alternatively releasable by a common locking member.

28. The structure defined in claim 27 wherein said sleeve has a longitudinal way within said wall between the exterior thereof and said aperture, said common locking member comprising a plunger movable longitudinally within said way.

29. The structure defined in claim 28 wherein said plunger has first, second, and third longitudinal positions within said way,

said plunger in said first position being effective so to secure said sleeve in said selected rotative positions within said casing and so to secure said plug rotatably within said aperture,

said plunger in said second position thereof being effective to release said sleeve for rotation within said casing while maintaining said plug within said aperture,

said plunger in said third position thereof being in said released condition thereof.

30. The structure defined in claim 29 wherein said internal surface portions of said casing have a plurality of detent recesses at said selected positions,

said sleeve having an opening between said exterior thereof and said way within which one detent member is carried for outward movement into locking engagement within a selected recess and inward movement out of such engagement,

said plug having an annular groove in its exterior,

said sleeve having an opening between said way and aperture within which is carried another detent member projecting into engagement within said groove to so secure said plug rotatably within said aperture,

said plunger having first and second obstructing portions which in said one position thereof respec tively obstruct movement of said detent members out of said selected recess and groove,

said plunger having a relieved portion which in said second position thereof frees said one detent member for movement out of said recess while said second obstructing portion maintains said other detent member within said groove,

said plunger having another relieved portion which in said third position of said plunger frees said other detent member for movement out of said groove.

31. The structure defined in claim 30 wherein said plunger is spring biased toward said one position and is manually shiftable against said bias consecutively to said second and third positions thereof.

32. The structure defined in claim 31 wherein said way and plunger have shoulders which face one another, a spring being compressed between said shoulders to provide said bias.

33. The structure defined in claim 32 wherein said casing, sleeve, plug, detent members, plunger, and spring are made of nonmetallic plastic material,

said spring, responsive to said movement of said plunger from said one position toward said third position, being compressed to solid condition prior to attainment by said plunger of said third position to prevent said second relieved portion from so freeing said other detent member whereby to prevent removal of said plug from said aperture.

34. The structure defined in claim 33 wherein said second locking means comprises a plunger within the wall of said plug movable manually to said released condition and returned to locking condition by a spring, the latter said plunger and spring being formed of nonmetallic plastic material.

35. The structure defined in claim 12 wherein said second locking means comprises a plurality of other detent recesses in said aperture wall at said selected positions of said plug,

another detent member carried by said plug movable outwardly into locking engagement within a selected other recess and inwardly out of engagement therewith.

and another locking member carried by said plug movable between said one position in which it ohstructs inward movement of said other detent member and another position in which it frees said other detent member for inward movement.

36. In combination, a bowling ball having a radial bore therein and an insert structure according to claim I mounted within said bore.

37. In combination, a bowling ball having a radial bore therein and an insert structure according to claim 4 mounted within said bore.

38. In combination, a bowling ball having a radial bore therein and an insert structure according to claim 9 mounted within said bore.

39. In combination, a bowling ball having a radial bore therein and an insert structure according to claim 12 mounted within said bore.

40. In combination, a bowling ball having a radial bore therein and an insert structure according to claim 19 mounted within said bore.

41. In combination. a bowling ball having a radial bore therein and an insert structure according to claim 26 mounted within said bore.

42. In combination, a bowling ball having a radial bore therein and an insert structure according to claim 32 mounted within said bore.

43. In combination, a bowling ball having a radial bore therein and an insert structure according to claim 34 mounted within said bore.

44. In combination, a bowling ball having a radial bore therein and an insert structure according to claim 35 mounted within said bore.

45. The structure defined in claim 1 wherein said hole has an axis which passes adjacent to but spaced from the center of the ball,

said end of said hole being movable relative to said surface responsive to rotation of said plug to positions other than said one rotative position thereof and responsive to rotation of said sleeve with said plug in said other rotative positions,

said hole axis having a point closest to said ball center which moves through a distance which is a predetermined fraction of the distance of movement of said hole end in response to said rotation of said plug and sleeve.

46. The structure defined in claim 45 wherein said fraction is about one half.

47. In combination, a bowling ball having a radial bore therein and an insert structure according to claim 45 mounted within said bore.

I *I l 

1. Insert structure adapted to be mounted within a radial bore in a bowling ball, said insert structure comprising, means forming a sleeve and mounting means adapted to mount said sleeve within such radial bore for rotation about an axis substantially coincident with a radius of the ball through the bore, said sleeve having a wall which defines an aperture therein having surface portions lying on a cylinder, the axis of which is angled in non parallel relation to the axis of rotation of said sleeve, means forming a plug engaged within said aperture for rotation relative to said sleeve about said aperture axis, said plug having a hole which is eccentrically located therein and which is adapted to receive a human digit, said sleeve and plug having end portions adapted to be located adjacent the surface of a sphere defined by the ball and said hole having an end which opens adjacent said surface, the angle of said aperture axis and the eccentricity of the location of said hole being so related that in one rotative position of said plug and sleeve relative to each other, said end of said hole is substantially centered with respect to said axis of rotation of said sleeve.
 2. The structure defined in claim 1 wherein said hole has an axis which is substantially parallel to that of said aperture.
 3. The structure defined in claim 1 wherein said hole has an axis which is angled in non parallel relation to that of said aperture.
 4. The structure defined in claim 1 wherein said mounting means comprises a casing adapted to be affixed within such radial bore, said casing having a wall with internal surface portions lying on a cylinder the axis of which is substantially coincident with a radius of the ball through the bore, said sleeve being engaged within said surface portions for rotation about the latter said axis relative to said casing, said casing having an end portion adjacent the surface of such sphere.
 5. The structure defined in claim 4 wherein said casing comprises a cup having a substantially cylindrical exterior and a substantially cylindrical interior which defines said internal surface portions, said sleeve having a substantially cylindrical exterior so engaged within said surface portions and said aperture wall being substantially cylindrical, said plug having a substantially cylindrical exterior so engaged within said aperture and said hole therethrough being substantially cylindrical.
 6. The structure defined in claim 5 wherein each of said casing, sleeve, and plug is formed of a nonmetallic material.
 7. The structure defiNed in claim 5 wherein in said one rotative position of said plug and sleeve, a first of said end portions of said sleeve at one side of said aperture is radially relatively thick and a first of said end portions of said plug radially contiguous thereto is radially relatively thin, a second of said end portions of said sleeve diametrically opposite from the first is radially relatively thin and a second of said end portions of said plug radially contiguous thereto is radially relatively thick.
 8. The structure defined in claim 7 wherein the combined radial thickness of said first portions is substantially equal to that of said second portions.
 9. The structure defined in claim 4 and including in addition first releasable locking means operable to secure said sleeve in selected rotative positions within said casing, and second releasable locking means operable to secure said plug in selected rotative positions within said sleeve.
 10. The structure defined in claim 9 wherein said sleeve has substantially cylindrical exterior surface portions engaged within said internal surface portions of said casing, one of said surface portions having an annular groove, and means projecting from the other of said surface portions into said groove to retain said sleeve rotatably within said casing.
 11. The structure defined in claim 10 wherein said groove is in said exterior surface portion of said sleeve.
 12. The structure defined in claim 9 wherein said first locking means comprises a plurality of detent recesses in said internal surface portions of said casing at said selected positions, a detent member carried by said sleeve movable outwardly into locking engagement within a selected recess and inwardly out of engagement with said recess, and a locking member carried by said sleeve movable between one position in which it obstructs inward movement of said detent member and another position in which is frees said detent member for inward movement.
 13. The structure defined in claim 12 wherein said locking member is carried within said sleeve wall between the exterior thereof and said aperture, said detent member being contained within an opening between said exterior of said wall and said locking member.
 14. The structure defined in claim 13 wherein said locking member comprises a plunger movable generally longitudinally within said wall, said plunger having an obstructing portion which in said one position of said plunger so obstructs said detent member and having a relieved portion which in said other position is aligned with said detent member to so free the same.
 15. The structure defined in claim 14 wherein said member comprises a ball.
 16. The structure defined in claim 14 wherein said plunger has an exposed end portion which in said one position thereof is adjacent said end portion of said sleeve, said plunger being spring-biased toward said one position and being manually shiftable against the bias toward said other position of said plunger.
 17. The structure defined in claim 16 wherein said sleeve wall has a longitudinally extending way therein which has a relatively small diameter portion and a relatively large diameter portion with a shoulder therebetween, said plunger having portions of relatively small and relatively large diameter which respectively fit movably within said small and large diameter portions of said way and having a shoulder between said small and large diameter portions, said small diameter portion of said plunger embodying said obstructing portion and relieved portion thereof, and a spring stressed between said shoulders to provide said bias.
 18. The structure defined in claim 17 wherein said relatively large diameter portion of said plunger has said exposed end portion.
 19. The structure defined in claim 9 wherein said second locking means comprises a plurality of detent recesses in said aperture wall at said selected positions of said plug, a detent member carried by said plug movable outwardly into locking engagement within a selected recess and inwardly out of engagement with the recess, and a locking member carried by said plug movable between one position in which it obstructs inward movement of said detent member and another position in which it frees such detent member for inward movement.
 20. The structure defined in claim 19 wherein said locking member is carried within the wall of said plug between the exterior thereof and said hole therein, said detent member being contained within an opening between said exterior of said wall and said locking member.
 21. The structure defined in claim 20 wherein said locking member comprises a plunger movable generally longitudinally within said wall of said plug, said plunger having an obstructing portion which in said one position of said locking member so obstructs said detent member and having a relieved portion which in said other position is aligned with said detent member to so free the same.
 22. The structure defined in claim 21 wherein said detent member comprises a ball.
 23. The structure defined in claim 21 wherein said plunger has exposed end portions which in said one position thereof are adjacent said end portion of said plug, said plunger being spring-biased toward said one position and being manually shiftable against the bias toward said other position of said plunger.
 24. The structure defined in claim 23 wherein said plug has a longitudinal way therein which has a relatively small diameter portion and a relatively large diameter portion with a shoulder therebetween, said plunger having portions of relatively small diameter and relatively large diameter which respectively fit movably within said small and large diameter portions of said way and having a shoulder between said small and large diameter portions. said small diameter portion of said plunger embodying said obstructing portion and relieved portion thereof, and a spring stressed between said shoulders to provide said bias.
 25. The structure defined in claim 24 wherein said relatively large diameter portion of said plunger has said exposed end portion.
 26. The structure defined in claim 9 and including in addition third releasable locking means operable to secure said plug rotatably within said aperture, said third locking means being cooperable with said second locking means when both are in released condition to free said plug for removal from within said aperture.
 27. The structure defined in claim 26 wherein said first and third locking means are alternatively releasable by a common locking member.
 28. The structure defined in claim 27 wherein said sleeve has a longitudinal way within said wall between the exterior thereof and said aperture, said common locking member comprising a plunger movable longitudinally within said way.
 29. The structure defined in claim 28 wherein said plunger has first, second, and third longitudinal positions within said way, said plunger in said first position being effective so to secure said sleeve in said selected rotative positions within said casing and so to secure said plug rotatably within said aperture, said plunger in said second position thereof being effective to release said sleeve for rotation within said casing while maintaining said plug within said aperture, said plunger in said third position thereof being in said released condition thereof.
 30. The structure defined in claim 29 wherein said internal surface portions of said casing have a plurality of detent recesses at said selected positions, said sleeve having an opening between said exterior thereof and said way within which one detent member is carried for outward movement into locking engagement within a selected recess and inward movement out of such engagement, said plug having an annular groove in its exterior, said sleeve having an opening between said way and aperture within which is carried another detent member projecting into engagement within Said groove to so secure said plug rotatably within said aperture, said plunger having first and second obstructing portions which in said one position thereof respectively obstruct movement of said detent members out of said selected recess and groove, said plunger having a relieved portion which in said second position thereof frees said one detent member for movement out of said recess while said second obstructing portion maintains said other detent member within said groove, said plunger having another relieved portion which in said third position of said plunger frees said other detent member for movement out of said groove.
 31. The structure defined in claim 30 wherein said plunger is spring biased toward said one position and is manually shiftable against said bias consecutively to said second and third positions thereof.
 32. The structure defined in claim 31 wherein said way and plunger have shoulders which face one another, a spring being compressed between said shoulders to provide said bias.
 33. The structure defined in claim 32 wherein said casing, sleeve, plug, detent members, plunger, and spring are made of nonmetallic plastic material, said spring, responsive to said movement of said plunger from said one position toward said third position, being compressed to solid condition prior to attainment by said plunger of said third position to prevent said second relieved portion from so freeing said other detent member whereby to prevent removal of said plug from said aperture.
 34. The structure defined in claim 33 wherein said second locking means comprises a plunger within the wall of said plug movable manually to said released condition and returned to locking condition by a spring, the latter said plunger and spring being formed of nonmetallic plastic material.
 35. The structure defined in claim 12 wherein said second locking means comprises a plurality of other detent recesses in said aperture wall at said selected positions of said plug, another detent member carried by said plug movable outwardly into locking engagement within a selected other recess and inwardly out of engagement therewith, and another locking member carried by said plug movable between said one position in which it obstructs inward movement of said other detent member and another position in which it frees said other detent member for inward movement.
 36. In combination, a bowling ball having a radial bore therein and an insert structure according to claim 1 mounted within said bore.
 37. In combination, a bowling ball having a radial bore therein and an insert structure according to claim 4 mounted within said bore.
 38. In combination, a bowling ball having a radial bore therein and an insert structure according to claim 9 mounted within said bore.
 39. In combination, a bowling ball having a radial bore therein and an insert structure according to claim 12 mounted within said bore.
 40. In combination, a bowling ball having a radial bore therein and an insert structure according to claim 19 mounted within said bore.
 41. In combination, a bowling ball having a radial bore therein and an insert structure according to claim 26 mounted within said bore.
 42. In combination, a bowling ball having a radial bore therein and an insert structure according to claim 32 mounted within said bore.
 43. In combination, a bowling ball having a radial bore therein and an insert structure according to claim 34 mounted within said bore.
 44. In combination, a bowling ball having a radial bore therein and an insert structure according to claim 35 mounted within said bore.
 45. The structure defined in claim 1 wherein said hole has an axis which passes adjacent to but spaced from the center of the ball, said end of said hole being movable relative to said surface responsive to rotation of said plug to positions other than said one rotative position thereof and responsive to rotation of said sleeve with said plug in said other roTative positions, said hole axis having a point closest to said ball center which moves through a distance which is a predetermined fraction of the distance of movement of said hole end in response to said rotation of said plug and sleeve.
 46. The structure defined in claim 45 wherein said fraction is about one half.
 47. In combination, a bowling ball having a radial bore therein and an insert structure according to claim 45 mounted within said bore. 